Preheat oven to 350 degrees.
Line bottom on 9-inch springform pan with parchment paper.
Over simmering water, melt together butter, chocolate, sugar and orange juice, stirring to blend.
Remove from heat; stir in liqueur and vanilla. Let cool; whisk in eggs, one at a time.
Pour into prepared pan. Bake for 40 to 50 minutes or until edges are slightly crusty and middle is just set. Let cool on rack.
Cover with plastic wrap and refrigerate for at least 12 hours or up to 24 hours.
Raspberry coulis:
Purée raspberries in food processor; press through sieve to remove seeds. Stir in sugar, and liqueur.
Invert cake onto serving plate.
Sift cocoa powder over cake and garnish with raspberries. Slice and serve with raspberry coulis.
